EveryBlock could have been successful with any number of designs, the interesting part about the site is the data and its organization. I agree that it's great looking, but a site doesn't have to be great looking to be a hit (Craigslist for example).
To me, it would have been nice to have the design to use as a starting point.
It also seems that it's part of the source code of the site.
When reddit went open source, they included their CSS, images, HTML, etc. I think this makes it easier to get going. Reddit and EveryBlock are going to continue to innovate enough to differentiate themselves from the clones.
I also hope they've included the mapping code/JavaScript. I haven't had a chance to look through the source to see if this is the case.
